Smart buoyancy compensation devices

ABSTRACT

Aquatic structures with adjustable buoyancy constructed in part with a vent valve for a buoyancy control device suitable for divers, where the vent valve may be opened by any combination of over-pressure, manual pressure relief or a powered means, where a force to a valve plug is applied by means of a spring that is constrained to prevent entirely lateral and angular movement but in which movement of the plug in the axis of the seat is unconstrained.

CROSS REFERENCE TO RELATED APPLICATION

This U.S. Non-Provisional patent application claims the benefit of U.S.Provisional Patent Application No. 62/458,532, filed on Feb. 13, 2017,and is incorporated herein by reference. This application is also acontinuation-in-part application of U.S. patent application Ser. No.15/607,609, filed May 29, 2017, which is a continuation-in-part of U.S.Pat. No 9,663,203, filed Feb. 19, 2016, the content all of which isincorporated herein by reference. U.S. Pat. No. 9,663,203 is acontinuation-in-part of U.S. patent application Ser. No. 13/432,063,filed Mar. 28, 2012, now abandoned and U.S. patent application Ser. No.14/059,496, filed Oct. 22, 2013, now abandoned, the content all of whichis incorporated herein by reference.

TECHNICAL FIELD

This description relates generally to aquatic structures and morespecifically to utilizing buoyancy control to raise and lower theaquatic structure.

BACKGROUND

A buoyancy compensator, buoyancy control device, BC, BCD, stabilizer, orthe like, is typically a piece of diving equipment with an inflatablebladder worn by divers to establish neutral buoyancy underwater andpositive buoyancy on the surface, when desired. In a BuoyancyCompensation Device (“BCD”), the buoyancy is typically controlled byadjusting the volume of air in the bladder. The bladder is typicallyfilled with gas from the diver's primary breathing gas cylinder via ahose from the regulator first stage, directly from a small cylinderdedicated to this purpose, or from the diver's mouth through the oralinflation valve. A means to add gas to a bladder in the BCD enables thediver's buoyancy to be increased, and vent valves allow gas to bedischarged to reduce the diver's buoyancy through a reduction in thewater volume displaced by the bladder.

Control of a diving buoyancy compensator is typically manual, andadjustment is required throughout a dive as the diver's weight reduceswith gas consumption, and the buoyancy of the diving suit varies withdepth as it compresses due to water pressure.

In aquatic applications, structures are often built to achieve varioustasks. For example, in aquaculture or “fish farming”, fish pens may bebuilt and tethered in the open ocean to raise fish for market. Suchaquaculture structures may be anchored in place and raised and loweredby mechanical equipment, such as wenches and the like. Buoyancy may beprovided by floats and the like to keep the structures from sinking.Also such structures may also be constructed to raise shellfish, seaweedand the like that may be of commercial value. In the course of operationof such structures, it may be desirable from time to time to raise andlower them in the water.

In other aquatic applications structures may be employed to raise andlower, and otherwise recover objects from the sea floor. In suchapplications, winches and other mechanical methods may be utilized tobring the object to the surface. In such applications, such as shiprecovery, a bag may be inserted in a ship's hold and inflated todisplace the water and raise the ship. However, in the applicationsdescribed above, little control over buoyancy is provided and thecontrol when provided tends to require direct involvement by an operatoror other personnel. Accordingly, it would be desirable to provideequipment and methods to control buoyancy in these applications that iscapable of automatically and remotely controlling buoyancy to raise andlower such aquatic structures.

As can be seen from the paragraphs above, a buoyancy compensator can bea valuable piece of equipment during a dive as it allows a diver toadjust his or her buoyance in order to achieve positive, negative, orneutral buoyancy depending upon conditions sensed or programed into thebuoyancy compensating device. There are other applications where it maybe advantageous to construct structures or equipment for aquatic use inwhich the buoyancy of such structures may be controlled based on adesired set of conditions. In particular, buoyancy control that could beapplied in such buoyancy controlled structures to raise and lower thestructure its self in the water, raise and lower objects in the waterthat have been captured by the structure, or otherwise position thestructure at varying depths in the water. It would be advantageous if abuoyancy compensator and its associated components could be used in suchapplications to adjust buoyancy for such structures. It would be offurther advantage if such buoyancy compensators could be programmedand/or remotely controlled so that they operate autonomously and/orremotely.

SUMMARY

The following presents a simplified summary of the disclosure in orderto provide a basic understanding to the reader. This summary is not anextensive overview of the disclosure and it does not identifykey/critical elements of the invention or delineate the scope of theinvention. Its sole purpose is to present some concepts disclosed hereinin a simplified form as a prelude to the more detailed description thatis presented later.

The present example provides various aquatic structures that may utilizeSmart Buoyancy Compensation Devices (“SBCD”) that can utilize dataanalytics and artificial intelligence to automate buoyancy control for awide range of aquatic applications. The exemplary SBCD system can bepre-programed and controlled remotely, which makes it amenable for useas a buoyancy control device to raise or lower various structures in thewater.

More specifically, the present invention relates to devices, techniques,and methods to manage the buoyancy of various underwater devices andstructures. A structure or application may utilize one or more smartbuoyancy compensation devices to control the buoyancy of the structureand to raise or lower the structure in the water. In the smart buoyancycompensation device, gas is added to a bladder or equivalent structurevia an electrically controlled gas valve, and vented by the simultaneousoperation of at least one of a plurality of typically pneumaticallyactivated vent valves. A control unit determines the period that thevalves should be opened via a process utilizing inputs from at least oneof a plurality of sensors typically measuring conditions such as depth,derivatives of the depth (the first derivate obtaining speed, and thesecond derivative the acceleration of the diver), and the like. The SBCDcontrol units typically utilize a novel combination of sensors to obtainthe ambient pressure, speed and acceleration of the structure within theaccuracy and resolution limits of practical sensors and ADC convertersor their equivalents.

Many of the attendant features will be more readily appreciated as thesame becomes better understood by reference to the following detaileddescription considered in connection with the accompanying drawings.

DESCRIPTION OF THE DRAWINGS

The present description will be better understood from the followingdetailed description read in light of the accompanying drawings,wherein:

FIG. 1 is a block diagram showing an exemplary buoyancy control systemfor raising and lowering an aquatic structure.

FIG. 2 is a diagram illustrating the abilities of a smart buoyancycompensation device utilized in diving that provides automated handsfree controlled descent, depth limit, hover, and controlled ascent.

FIG. 3 shows the SBCD buoyancy tube structure as utilized in aquacultureapplications.

FIG. 4 shows a top view of an SBCD controlled aquatic structure havingsections of adjustable depth rings from which seaweed may hang as itgrows (seaweed farming).

FIG. 5 shows a SBCD harvest bag recovery system.

Buoyancy bag alternative to rigid shell buoyancy control. Radio orultrasonic controlled from surface boat with power from generators andcompressor for air supplies. No surface buoys.

FIG. 6 shows a SBCD lobster pot retrieval system.

FIG. 7 shows a SBCD salvage operations system.

FIG. 8 shows a SBCD unexploded bomb removal system.

FIG. 9 shows a SBCD trawler, or hanging fishing net system.

FIG. 10 shows a SBCD smart buoy aqua-forest.

FIG. 11 shows a SBCD controlled fish pen system.

FIG. 12 shows a SBCD winch activated depth control system.

FIG. 13 shows a SBCD water pressure depth control system.

FIG. 14 shows cross sections of the hard shell pipe buoyancy adjustingbuoy.

FIG. 15 shows a SBCD depth and buoyancy control system for non-parallelmoorings.

FIG. 16 shows a vent valve according to the present invention in thestate where the valve is closed. The valve in this example and thefollowing drawings includes provision for powered actuation, which isdesirable but not a necessary feature of the valve.

FIG. 17 shows a vent valve according to the present invention in thestate where the valve is open through manual actuation or over-pressure.

FIG. 18 shows a vent valve according to the present invention in thestate where the valve is open through automatic actuation channel only.

FIG. 19 shows a vent valve according to another embodiment of thepresent invention in the state where the valve is closed throughautomatic actuation channel only.

FIG. 20 shows an example of a SBCD diving vest.

Like reference numerals are used to designate like parts in theaccompanying drawings.

DETAILED DESCRIPTION

The detailed description provided below in connection with the appendeddrawings is intended as a description of the present examples and is notintended to represent the only forms in which the present example may beconstructed or utilized. The description sets forth the functions of theexample and the sequence of steps for constructing and operating theexample. However, the same or equivalent functions and sequences may beaccomplished by different examples.

The examples below describe a smart buoyancy compensation device forcontrolling buoyancy of an aquatic structure. Although the presentexamples are described and illustrated herein as being implemented in anaquaculture system, the system described is provided as an example andnot a limitation. As those skilled in the art will appreciate, thepresent examples are suitable for application in a variety of differenttypes of commercial diving, government/military, scientific andcommercial fishing/aquaculture such as multi species aqua forests, fishpens, shellfish growing structures, biofuels production, seaweed growingstructures, salvage systems and the like.

According to the particular application, SBCDs are utilized to maintainor move the relative position of farming structures to a depth sent tothem by a master control unit. Such a system avoids any out of plainbuckling by adjusting the individual buoyancies at the same speedregardless of different loads that may be applied to them.

Such systems advantageously allow a crop and structure that is typicallyprotected from ocean surface pollution and any near surfaceparasites/impurities, storm, tidal race, surface shipping traffic andthe like. Depth can be controlled on a time basis or in response toambient conditions and nutrient cycle needs for a particular aquaculturecrop. The SBCD systems may provide day light hours hold or return tonear surface optimum position. Typical conditions the SBCD is capable ofaccommodating include an at sunset drop to 30 meters depth, when largerwaves or shipping activity is detected then drop to 5 meters, and forharvesting a return to the surface.

The buoyancy controlled structures described herein are typicallydesigned to autonomously lift/lower objects underwater without miles ofexpensive ropes/chains, cranes, diving crews, and the like.

The SBCD controlled systems described herein are important to theoperation of low cost seaweed growing systems to maintain and changedepth without either buoys or anchors. This capability means thatfree-floating structures can submerge to allow ship passage, avoidstorms, access nutrients, or enter currents moving in a differentdirection than the surface current. The issue of efficient buoyancycontrol for underwater seaweed rigs and the like may be provided by thebuoyancy control systems described below.

FIG. 1 is a block diagram showing an exemplary buoyancy control systemutilized for raising and lowering an aquatic structure 109. The SBCD 101monitors and controls buoyancy. At least one of a plurality of SBCDs maybe utilized in any given aquatic system to control buoyancy of anaquatic structure. In particular the SBCD has the ability to control thebuoyancy of a structure changing its depth at any rate, or rates, andcausing it to hover at a desired depth. Since an objective is typicallyto hover at a fixed elevation above the seafloor, precise autonomous(computer) control of the valves and pumps or a buoyancy bladder systemis important to achieving autonomous, precise, and trouble freeoperation.

The SBCD controller 103 typically provides the following buoyancycontrol: (1) maximum depth, (2) maximum descent speed (typicallypre-set), (3) maximum ascent speed (typically pre-set), (4) controlledascent (at an exemplary 30 ft/min) with stops if desired, and if thecomputer calculates that they are required, (5) emergency ascent (at anexemplary controlled maximum speed of 60 ft/min), (6) level hold(maintains the structure depth, (7) automatic ascent to the surface whencomputer calculates from the buoyancy tank sender that the air remainingin the tank is at set level.

The SBCD 101 is an automatic buoyancy system that includes a controlunit 103 having a processor 119 and memory 121 with software or firmwareproviding unique buoyancy control processes, valves 123 to convertsignals from the processor to inflation and deflation actions. Also,part of the system are at least one of a plurality of sensors 117coupled to at least one of the SBCD control units that provideinformation on ambient conditions (including depth, pressure, current,velocity, acceleration, or any parameter that may be needed as known tothose skilled in the art to control buoyancy ascent, descent and thelike). SBCD system power may be provided by batteries, an external solarpanel or the like (not shown).

The processor 119 controls electro/pneumatic supply valves 123 which inturn control unique vent valves 107 (injection and exhaust valves).Commands to the various valves are typically either stored on themicroprocessor or sent to it, or a combination of the two. Supply valves123 are typically supplied air from a source 125 that can be a tank ofcompressed air, an external air-line, or the like.

The SBCD uses a processor (processor includes controller, PLLCs,microprocessors, or their equivalents) 103 linked to sensors on theobject to be controlled to note conditions including water pressure andchanges in water pressure to calculate the depth and speed of thedevice.

A bladder or buoyancy device 105 that may change volume 111, is providedfor buoyancy.

At least one of a plurality of automated exhaust, or vent valves 107 iscoupled to the bladder to release air 115 to decrease buoyancy. The ventvalves 107 are in electrical and/or pneumatic communication with thecontrol unit 103. Vent valves 107 such as described in “BOUYANCY VESTVENT VALVE WITH RELIABLE SEATING” U.S. Pat. No 9,663,203, issued Jun.16, 2016, the disclosure of which is incorporated herein in itsentirety, may be employed in the SBCD system.

The structure 109 may be any of the structures described herein, orequivalently any type of aquatic structure in which buoyancy is soughtto be controlled.

In the case of a plurality of SBCDs they may be networked under a mastercontroller (not shown) or may function independently if desired. SBCDs,as implemented for the systems described herein, typically include aplurality of communicating SBCDs to raise, lower, and hover 113 any sizeocean structure or system, even with large waves passing overhead.

For example: (1) SBCDs may control the top of an exemplary raftseaweed-growing structure to hover an exemplary 1 meter+0.2 m, below thetroughs of 2 meter high waves, (2) a wave motion/force sensor disposedon the top of a structure communicates to the SBCDs causing it to changehover depth in real time to optimize the sunlight available to seaweedand extend the life of the structure, reducing costs (During exemplary 1meter high waves, the structure might be an exemplary 0.5 m below thetroughs. During exemplary 10 meter storm waves, the structure might bepositioned to an exemplary 15 meters below the troughs to reduce forceson the structures, seaweed, and anchors.), (3) SBCDs can maintain acertain depth on towed components such as a rope or ribbon movingto-from shearing in an exemplary harvest bag, or maintaining the top ofan exemplary 20,000 ton full harvest bag net at an exemplary 25 meterdepth while it is towed/winched a few hundred kilometers or so, by atransport vessel.

SBCD System Operation

The control unit (FIGS. 5-7 of U.S. Pat. No. 9,663,203, issued Jun. 16,2016, the disclosure of which is incorporated herein in its entirety)typically operates as follows:

Inflation—When the processor decides that air should be added to theSBCD bladder, an electric pulse is sent to an inflationelectro-pneumatic solenoid valve, which opens allowing low pressure airto enter the SBCD bladder via the inflation port. The computer decidesthe length of the pulse, and thus, the amount of air added to thebladder.

Deflation—When the processor decides that air should be removed from theBSCD bladder, an electric pulse is sent to a deflation electro-pneumaticsolenoid, which opens allowing low-pressure air to enter a smallcylinder. The piston in this cylinder is connected to a deflation ventvalve. When this deflation vent valve opens it allows air in the SBCDbladder to escape via a port in the controller. The computer decides thelength of the pulse, and thus, the amount of air added to the bladder.

Artificial Intelligence—The SBCD system is designed to emulate a varietyof conditions for operation of the structure.

In a typical system when air is added or removed from the bladder, alonger pulse is sent (rather than a series of short pulses). Then, aftera predetermined time a correction may be made if determined to beneeded. Pulse length is typically dependent upon a measured deviationfrom a desired speed or depth. In addition, small changes in buoyancymay be filtered out if desired.

FIG. 2 is a diagram illustrating the abilities of a smart buoyancycompensation device utilized in diving that provides automated handsfree controlled descent 201, depth limit 207, hover 205, and controlledascent 203. The diving SBCD allows a diver to change depth at any rateand hover at any desired depth. SBCDs are used in scuba diving equipmentto enable the diver to have hands free controlled descent, depth limit,hover, and controlled ascent.

A description of a diving buoyancy control device suitable formodification as known to those skilled in the art to achieve thefunctions described herein is further described in “BOUYANCY VEST VENTVALVE WITH RELIABLE SEATING” U.S. patent application Ser. No.15/607,609, filed May 29, 2017, the disclosure of which is included inits entirety by reference.

SBCD commands utilized from such a diving system can include: (1) Stayat the depth commanded, (2) Descend to a new depth at a controlledspeed, and (3) Rise to a new depth at a controlled speed. The controllerthen sends signals to the valves to adjust the buoyancy in the bag byreleasing or adding compressed gas from or to the buoyancy bag,typically incorporated into a diver's vest.

In such a system advantageously utilized in a SBCD, the depth and speedof the device, and thus the system, are monitored around 10 times asecond and adjustments made until the commanded conditions are met. Asystem of artificial intelligence is used to make human styleadjustments rather than many small adjustments. This tends to savecompressed gas and power.

FIG. 3 shows the SBCD buoyancy tube structure 301 as utilized inaquaculture applications. For aquaculture applications, SBCDs typicallyuse a buoyancy tube, that may be partially inflated to hover at selecteddepth. Near the surface the tube is inflated and is almost completelydeflated at depth. The air in the tube combined with the ballast (rocks,or the like) 303 keeps the overall structure neutrally buoyant. The tubemay also house the SBCD controller 103.

The fundamental principle of the SBCD is that it inflates or deflates abuoyancy control unit which can be a buoyance bag, or bladder structure(for example 105 of FIG. 1), or rigid buoy that is inflated by a gas orother gas. The bladder may also be equivalently replaced by a rigidstructure 305, such as a spherically shaped object. By removing,typically by pumping, or the like.

FIG. 4 shows a top view of an SBCD controlled aquatic structure havingsections of adjustable depth rings 403 from which seaweed may hang onbands 401 as it grows (seaweed farming). In this application, the SBCDsoperate to control the structure having more inertia and hovering closerto the water surface. The structure shown can change depth at any rateand hover at any desired depth as controlled by a SBCD. For aquaculture,the SBCD's may use the above described buoyancy tube, that is partiallyinflated to hover at a selected depth.

The SBCD will slowly adjust the depth over months as sea life (seaweed,crustaceans, etc.) grow and change the net buoyancy of the structure, orover minutes should any forces try to move the system from its setdepth.

The SBCD senses its depth for an exemplary 10 times a second, and canadd and release air to and from the buoyancy tube in tenths of a secondincrements.

Without this precise control, minor depth excursions, even the changingpressure of waves above the structure, would cause changes in its depth.By deflating the tube, the structure can be taken to an exemplary setdepth (up to 1000 m) at a controlled speed.

To ascend, the SBCD may add air to the bag. If left unadjusted, thesystem would rise at an uncontrollable increasing speed because of theexpansion of the tube, but the SBCD releases air to control the ascentspeed to a pre-set maximum rate.

In particular, for seaweed farming buoyancy tubes are attached tosections of the farming system. The farming system is formed from aseries of concentric rings of tubes, the largest being up to 9 kmdiameter. Seaweed grows on bands hanging from radial lines hanging fromthe rings. In an exemplary application, over 50,000 buoyancy tubes andassociated control systems may be required per farming system. Eachbuoyancy tube has an exhaust valve(s), computer and controller coupledto it. Each computer is linked to a central control which issuesprescribed depth commands. And finally, each computer is autonomous intaking its tube to the required depth and maintaining that depth.

This application also utilizes communication between land/controlplatform and the SBCDs; between SBCDs; and between remote sensors andSBCDs. A pressure/depth sensor (not shown) hanging an exemplary 10meters below the structure may be utilized to avoid SBCDs depth“hunting” due to waves.

FIG. 5 shows a SBCD harvest bag recovery system. Once cut from theseaweed farm, the seaweed is transported to a processing station in abag 501 containing up to an exemplary 20,000 tons of seaweed. The bag istypically towed 503 under water. In this example, an automatic buoyancysystem 505 is coupled to the bag to maintain a prescribed depthregardless of the angle of tow, which tends to avoid having the bagcolliding with the farming system or shipping.

FIG. 6 shows a SBCD lobster pot retrieval system. This system includes aSBCD 101 attached to lobster pot traps 601 so they can be easilyretrieved. The SBCD-controlled lobster trap can be signaled 603 by theboat 605 to ascend at less than an exemplary 0.1 m/sec to the surfacefor collection by a boat 605.

In this example, an automatic buoyancy system is attached to a lobsterpot. An antenna buoy 607 on the surface is connected to the buoyancycontroller 101 on the pot 601 with an antenna cable 609. The lobsterfisherman sends a signal to the pot as he approaches the vicinity of thebuoy, thus, speeding up the retrieval time as no winching from theseabed is needed. The pot rises at a controlled rate and is picked up bythe boat. When re-baited the pot is returned to the sea bed at acontrolled speed using the SBCD system.

FIG. 7 shows a SBCD salvage operations system. In this applicationautomatic buoyancy systems with large bags 701 are attached to theobject (ship, plane, etc.) 703. A signal 705 to inflate the bags can begiven from a central point to at least one of a plurality of BCDs 706via a radio signal 705. This signal can be made by wire, radio, orultrasonic means, but is typically communicated via wire. The signal istypically picked up by a buoy with a receiving antenna 707, thattransfers the signal to the SBCDs via a cable. Each controllerautonomously inflates and deflates its bag 701 to maintain a predefinedascent speed. In the case of ancient relics, a very slow ascent rate istypically necessary to avoid damage to the object 703. The SBCD systemuniquely enables this speed to be maintained.

FIG. 8 shows a SBCD unexploded bomb removal system. In this systemapplication utilizing an SBCD, an automatic buoyancy system 809(including a buoyancy bag 807) or systems is attached to the bomb 811.Signals can be sent to the controllers 809 by wire, radio, or ultrasonictransmission 801 to give adjustment commands to a buoy 803 with areceiving antenna and in communication with the SBCD via a cable 805.Each controller then maintains its prescribed speed or depthautonomously. A slow ascent is maintained avoiding detonation of thebomb. On conventional bomb retrievals, divers are typically required inthe water to control the speed. There is no need for manned operationswith the above described system.

FIG. 9 shows a SBCD trawler, or hanging fishing net system. This systemis used to control the depth of trawled or hanging fishing nets 911. Aplurality of automatic buoyancy systems 907, 909 are attached to fishingnets. The nets are then controlled to prescribed depth by each systemindependently. The systems can be adjusted by the fishermen by signals901 sent to the controllers by wire, radio, or ultrasonic means,received by an antenna buoy 903 and transmitted to the SBCDs via a cableor cables 905. The nets can be raised to the surface on a radio commandfrom the fishing boat.

FIG. 10 shows a SBCD smart buoy aqua-forest. In this system aretractable central control master unit 1001 is deployed to the surfaceto monitor roughness of the seas and detect high currents 1002. Themaster unit may also be withdrawn, or retracted 1005. It is coupled to aplurality of SBCDs 1011 with corresponding buoyancy devices 1009, eachcoupled to a corresponding aqua forest structure 1013. Each aqua forestunit is strung 1013 together in series with each end tethered to aseafloor anchor 1007. SBCDs may also be disposed in each anchor cableend 1015, 1007. In alternative examples, individual aqua forests may bearranged in alternative structures such as grids and the like.

Aqua-forestry generally refers to an artificial eco system analogous tothat of a kelp forest. However, in an aqua-forest, any type of seaweedmay be utilized in conjunction with desired fish and shellfish species,including combinations of penned finfish, shellfish, seaweed, free rangefish, and crustaceans. Shellfish grown around fish pens tend to removeboth sea lice and fish feces. The aqua-forest approach to aquaculturemay also decrease the cost of finfish aquaculture.

FIG. 11 shows a SBCD controlled fish pen system. SBCDs automatically addor remove air buoyancy to maintain desired structure buoyancy. Thesystem may be radio or ultrasonic controlled 1101 from a surface boat orshore station. Advantageously there are a reduced number of, or nosurface buoys needed. Also, there is no need for expensive anchorsand/or moorings requiring regular maintenance and repair. A cagestructure 1109 is provided to contain the fish, and it is fitted withSBCDs 1105 including buoyancy structures 1103 and optionally gascylinders 1107 for systems injecting gas to control buoyancy.

In alternative examples, aqua-forestry can be constructed intrampoline-like layers in the pen structure. The layers allow, finfish,shellfish, and seaweed all share the same area in substantially verticallayers or arrangement. The shellfish and seaweed might be denser thanwhen they are farmed separately from finfish due to the improvednutrient recycling and/or nutrient remediation by substantiallycollocating the species to form an artificial forest. The finfish maycost-effectively enjoy more productivity per area with less finfishdensity per water volume. The finfish's lower volume density should helpreduce the spread of disease and pathogens.

FIG. 12 shows a SBCD winch activated depth control system. This SBCDcontrolled winch system may be used in conjunction with the previousexamples to replace the previously described buoyancy chambers in whichbuoyancy is controlled by adjusting air volume of pumping water in arigid vessel and compressing the air contained in it. Here, a buoy 1209of fixed positive buoyancy is tethered to the winch via a cable 1203,and it is simply raised and lowered (along with any structure coupled toit) under control of the SBCD 1207 attached to the buoy (and coupled tothe winch via a control cable 1205) by a winch 1201 located on the seafloor. This system may be wire, radio, or ultrasonic controlled from asurface boat or shore station (not shown). By using a sea floor anchoredsystem surface buoys are reduced or eliminated.

FIG. 13 shows a SBCD water pressure depth control system. As previouslymentioned in the above paragraphs, water pressure may be used in a rigidvessel 1307 containing a compressible gas 1313 rather than a bladder toprovide a variable buoyancy device. Rigid partially water-filledspheres, pipes, or the like may use electric pumps 1311 to remove or addwater 1315 to change buoyancy. As in previous examples, radio orultrasonic control from a surface boat with power from generators orsolar panels may be utilized. The system may be further simplified byutilizing workboat mounted pumps to pump water (or alternativelycompress air or pump a vacuum).

Under SBCD 1309 control, a reversible pump 1311 attached to a rigidvessel 1307 that is partially filled with air either fills the vesselwith water 1305, compressing and reducing the air volume, or removeswater increasing the air volume 1301 making the structure more buoyant.Also, a neutral buoyance state may be obtained 1303 by adjusting theproportions of water and air.

FIG. 14 shows cross sections of the hard shell pipe buoyancy adjustingbuoy. Whether utilizing bladders or rigid buoyancy devices 1401, theSBCD systems can effectively adjust the buoyancy of collapsing(balloon-like) or hard-shell gas containers of this figure so that: asubmerged structure can hover a few feet below wave troughs at aconstant distance from the sea floor with a tropical storm passingoverhead, and submerged structures can be made to move up or down orhover at constant depth even with changing current.

The physical buoyancy adjustment is made by adding 1403 or removing 1404water (using compressing air, or pumping water in or out) inside rigidcylinders 1401 or spheres. The cylinders can be as simple as HDPE-coatedcorrugated steel storm drain pipe with crush depth near the maximumexpected. The figure shows two ways to compress or pull a vacuum in thepipe sections. In the Aqua-Forestry context, most pumping is done slowlywhen the structure is near the ocean surface. The buoyancy only changesby opening the valve moving water. The rigid structure means buoyancydoes not change with changing depth. For months at a time, the structureis on the surface with slowly increasing air volume to balanceincreasing biomass (shellfish, barnacles).

Regarding the pressures, shown in the left side of the figure shows aversion where a workboat-mounted pump “charges” the cylinders with airor vacuum while harvesting the heavy crop (shellfish). This simplifiedarrangement is appropriate for current shellfish farming. The right sideof the figure represents systems conditions with distributed pumps andsolar power panels mounted on the structure.

In general, pumping water is much more energy efficient than iscompressing air. Submersible pumps are off the shelf and commonlyavailable. The amount of energy storage will be determined by what isneeded to create overall positive buoyancy when returning from maximumsubmergence depth. A moored Aqua-Forestry system might only need tomatch the shellfish-paced change of buoyancy. The current might pushmoored Aqua-Forests to the seafloor. Conversely, reduction of currentallows moored Aqua-Forests to pop up. With unmoored Aqua-Forests, alittle stored energy may be needed to switch from neutral to positivebuoyancy at max depth. Max depth and rate of depth change is limited bythe sea-life's sensitivities. The obvious stored energy could be gaspressure in containers, a central cache of high-pressure air, orbatteries for the pumps.

FIG. 15 shows an SBCD depth and buoyancy control system with nonparallel moorings. Existing structures farming sea vegetables (akaseaweed), shellfish, or penned finfish (sometimes combinations) oftenemploy trapezoidal and single point moorings 1511. Without depth andbuoyancy control, the lead buoy size and the mooring line horizontallength are typically established by the maximum surface current and waveheight. This is because the aft buoy 1501 will remain on the surface,exposing the entire structure to the maximum waves even should the leadbuoy 1503 be pushed deep below the surface by the strong current 1509associated with powerful storms.

The lead buoy may advantageously incorporate SBCD depth and buoyancycontrol 1513. In contrast, an Aqua-Forestry system equipped with a SBCDcontrol system sinks 1507 intermediate and aft buoys as the current, orthe wave height increase beyond a sub-maximum set limit. The controlover intermediate and aft buoy sinking is such that they may hover 1507at the same elevation as the lead buoy, and would return to the surfacewith the lead buoy. For example, if the structure grows sea vegetableadequately when it remains on the surface 1505 for 90% of the daylighttime, the components are all designed for two situations: (1) surfacecurrent and waves that are smaller than the design situation 90% of thetime; and (2) hover-depth/elevation current and wave water particlevelocities that occur during the extreme event at the hover depth.(Water particle velocities will be less than 10% of the surface, currentwill generally be slightly less than the surface current. The currentdirection can change more than 180° as a tropical storm passesoverhead.)

Vent Valve

In the following paragraphs reference is made to a BCD bladder. The formof the bladder is not important; the present invention many be appliedto many different types of bladders. The sole special requirement forthe bladder to be used with the present invention is that the ventvalves shall be arranged such that there is an open gas path from thegas in the bladder to one of the vents. At least one vent valve isrequired to fulfil this requirement depending on the range of diverattitudes for which the vent function is available.

FIG. 16 shows a vent valve according to the present invention in thestate where the valve is closed. The valve in this example and thefollowing drawings includes provision for powered actuation, which isdesirable but not a necessary feature of the valve.

FIG. 17 shows a vent valve according to the present invention in thestate where the valve is open through manual actuation or over-pressure.

FIG. 18 shows a vent valve according to the present invention in thestate where the valve is open through automatic actuation channel only.

FIG. 19 shows a vent valve according to another embodiment of thepresent invention in the state where the valve is closed throughautomatic actuation channel only.

The vent valves in example embodiments shown in FIGS. 16-19 have aconventional manual pull dump 33 in addition to a pneumatically orhydraulically powered piston 27. The pull dump may be on a cord 35 or alever. A spring 5 applies a pressure to a valve plug 29 to close a seat30), but which can be overridden by any combination of manual pullaction, over-pressure or in these embodiments the powered actuation ofthe piston. The vent valve shown in FIG. 16 also comprises an innervalve plug 15; however, the vent valve according to another embodimentshown in FIG. 4 comprises only one main valve plug 29.

A compression spring 5 is constrained by walls 8 for more than half itslength, which prevents entirely the spring moving laterally side to sidein the drawings. The walls 8 can be arranged from opposite sides of thespring 5 or the walls 8 can have another configuration. The compressionspring 5 may be a wire spring or a wave spring, or any other type ofspring that applies a force to the valve plug 29 towards the directionof the seat 30.

A compression spring 5 will apply an uneven force to the plug 29.Without further constraint, this would tend to allow the plug 29 to moveat an angle with respect to the seat 3. To prevent that angularmovement, the plug 29 is attached to a guide 9 that maintains the plug29 such that the face of the plug 29 is parallel to the seat 30 at alltimes. In FIGS. 17 and 18 the guide 9 is constrained by a cylinder thatforms part of the outer cover 1), and in FIG. 19 the guide 9 isconstrained by the wall 8 that restricts the spring 5. It is highlypreferable that the end of the guide remains outside the cylinder thatit moves in, to prevent angular forces jamming the guide 9 in thecylinder.

A hose 7 carrying the gas from the inflator to the actuators ispreferably a narrow bore hose. Kynar hoses are available with a 0.8 mmbore and an outer diameter of 3.6 mm, which have the effect of limitingthe maximum flow rate when used with typical BCD gas supply pressures toaround 20 liters of gas flow per minute, and have a burst pressureexceeding the gas supply cylinder high pressure, such that if the firststage cylinder pressure regulator were to fail, then the hose 7 wouldnot rupture, and therefore there is no risk of the bladder in the BCDbeing inflated suddenly. Moreover, use of a very small bore hose meansthat should the hose break, the flow rate into the bladder is much lowerthan the minimum vent rate if the diver uses the manual vent controls onthe vent valves.

A one-way valve 31 is preferably fitted, and the one-way valve 31 ispreferably of an umbrella flapper valve construction to provide apositive cracking pressure to prevent water ingress into the BCD whenthe valve is open.

Vent valves with the features shown namely an input 7, (pressure inwhich causes a piston 27 to move and open a plug or stopper 29),allowing gas in the bladder to escape through a one-way valve 31. Amanual pull-dump 33 is preserved in the preferred embodiment, allowingmanual operation of the vent by the diver at any time. The pull-dumpcord 35 may be singular or may be combined.

A novel feature of the vent valves in the preferred embodiment is theuse of a wave spring to apply even pressure to the plug 29 such thatseats evenly.

The use of the wave spring reduces the difference in the spring forceacross the plug 29 and hence reduces the angle it tries to adopt withrespect to the valve seat 30. A wave spring is a type of compressionspring built from a series of thin washers that have a wave-likeprofile. Compressing the washers, which are normally welded together,results in having a reactive force that is even around the circumferenceof the spring. A wave spring can also provide a greater extension for aparticular spring force and spring bound size than a conventional wirecompression spring, which can be advantageous in this application.

A key feature of the vent valve is that the plug 29 is not firmlyattached to the piston 27, such that pulling the plug 29 via the cord 35causes the plug 29 to lift off the seat 30 without the piston 27 havingto move. The seat at the top of the piston 27 need not be attached tothe plug 29.

In all FIGS. 16-19, the valve plug 29 is not fixed to the pneumaticpiston rod 20: the rod can push the inner valve plug 15 in theembodiment in FIGS. 1-2, and the main plug 29 in FIG. 19, but does notprevent over-pressure from moving the plug to open the valve, norprevent manual actuation opening the valve.

In the case of FIG. 19, the valve plug 29 is limited in its movement byadjustment of an exterior cap to the valve to provide a limited orrestricted instantaneous flow rate. In that embodiment, theinstantaneous flow rate through the over-pressure action is also limitedin applications where that is desirable.

In FIGS. 16-18, the automatic actuation of the valve does not move themain valve plug 29, but moves only the inner valve plug 15, throughwhich gas flows. The instantaneous flow rate through that secondaryvalve comprising the inner valve plug 15 and seat is defined by choiceof vent hole dimensions. This enables the automatic actuation of thevalve to use a much lower instantaneous flow rate than that when thevalve is opened manually or through over-pressure. For optimum automaticbuoyancy control, a ratio of 8:1 or 16:1 is desired between theinstantaneous flow rate in the over-pressure role and the instantaneousflow rate in the power (automated) actuation role.

The pneumatic power may be provided by an arrangement of gas valves thatapply a lower gas pressure, such as 9 bar, to the hose 7 to activate thevent valve, but which in the quiescent or inactive state opens the gasline to the BCD bladder. When the gas hose 7 is a small bore hose, thenthe volume of the gas vented to the bladder may be kept to a negligibleamount.

An alternative to the pneumatic power to activate the vent valve is byuse of a bellows containing a liquid such as alcohol or water orsilicone oil, and pressure on the bellows by the user causes pressure tobuild up in the hose 7 and the valve to be opened. The spring bias tothe bellows causes the liquid to pull back the piston when the pressureis removed. The pressure may be through a lever or directly on thebellows.

The bellows or the hose 7 have a means through which gas can be drainedand fluid topped up, but such means may be in the form of a nipple orfilling point; there is no need for a hydraulic reservoir. During thefilling process, sufficient provision should be made for the thermalexpansion of the hydraulic liquid. This can be accommodated by a partialfill such that expansion of the liquid extends the bellows andcontraction causes them to shrink in size, but leaving sufficientmovement for the manual action.

The bellows may be implemented in a variety of forms, including a thickwalled balloon such as a silicone molding, or it may be a telescopingmolding, or it may be a series of telescoping elements with 0-ringseals.

FIG. 20 Shows an example of a SBCD diving vest. The vest shownadvantageously includes, in particular, a controller 5 and embeddedprocesses that may be adapted for use in the abovementioned systems. Thediving vest and its associated components, including processes forcontrolling dive parameters that may be adapted to SBCD use, are morefully described in co-pending patent application “BOUYANCY VEST VENTVALVE WITH RELIABLE SEATING” U.S. patent application Ser. No.15/607,609, filed May 29, 2017, the disclosure of which is incorporatedherein in its entirety.

Those skilled in the art will realize that the terms for a body of waterused herein including lake, ocean, sea, river, and the like and are notmeant to be limiting to the particular use of the examples describedherein to any particular body of water.

Those skilled in the art will realize that the process sequencesdescribed above may be equivalently performed in any order to achieve adesired result. Also, sub-processes may typically be omitted as desiredwithout taking away from the overall functionality of the processesdescribed above.

Those skilled in the art will realize that storage devices utilized tostore program instructions can be distributed across a network. Forexample a remote computer may store an example of the process describedas software. A local or terminal computer may access the remote computerand download a part or all of the software to run the program.Alternatively the local computer may download pieces of the software asneeded, or distributively process by executing some softwareinstructions at the local terminal and some at the remote computer (orcomputer network). Those skilled in the art will also realize that byutilizing conventional techniques known to those skilled in the art thatall, or a portion of the software instructions may be carried out by adedicated circuit, such as a DSP, programmable logic array, or the like.

1.-9. (canceled)
 10. An aquatic structure comprising: a mechanicalstructure; a control unit attached to the mechanical structure, thecontrol unit including: one or more sensors; a processor; and memory;one or more valves configured to be controlled by the control unit, theone or more valves coupled to a pressurized air supply; a buoyancycompensation bladder configured to receive air from the pressurized airsupply as controlled by the one or more valves; and a vent valve coupledto the control unit configured to release air from the buoyancycompensation bladder; wherein the control unit determines to add orrelease air to or from the buoyancy compensation bladder based at leastin part on one or more operation functions.
 11. The aquatic structure ofclaim 10, wherein the one or more sensors comprise a pressure sensor.12. The aquatic structure of claim 10, wherein the one or more sensorscomprise means for detecting wave motion; and wherein the control unitis configured to release air from the buoyancy compensation bladder inresponse to detecting a wave height above a threshold.
 13. The aquaticstructure of claim 10, wherein the one or more sensors comprise acurrent sensor.
 14. The aquatic structure of claim 10, wherein thecontrol unit is configured to control the one or more valves and thevent valve to control an ascent, to control a descent, and to maintain alevel hold of the mechanical structure.
 15. The aquatic structure ofclaim 10, wherein the control unit is configured to control the one ormore valves and the vent valve to control a volume of the buoyancycompensation bladder, the one or move valves including a main valve plugand an inner valve plug; wherein the main valve plug is configured toallow a first air flow, and wherein the inner valve plug is configuredto allow a second air flow that is less than the first air flow.
 16. Theaquatic structure of claim 10, wherein the buoyancy compensation bladdercomprises a rigid body.
 17. The aquatic structure of claim 16, furthercomprising an electric pump, wherein a buoyancy of the buoyancycompensation bladder is changed by using the electric pump for adding orremoving water to an interior of the buoyancy compensation bladder. 18.The aquatic structure of claim 10, wherein the mechanical structurecomprises a fin fish cage.
 19. The aquatic structure of claim 10,further comprising an antenna buoy for receiving remote instructions andtransmitting the remote instructions to the control unit via a cable.20. The aquatic structure of claim 10, in which the processor isconfigured to operate in the one or more operation functions includingone or more of a harvest bag recovery system, a lobster pot retrievalsystem, a salvage operations system, a unexploded bomb removal system, ahanging fishing net system, a smart buoy aqua-forest, or a controlledfish pen system.
 21. An aquatic structure comprising: a buoyancycontroller; memory storing computer-executable instructions that, whenexecuted, cause the buoyancy controller to perform operationscomprising: receiving data from one or more sensors; receiving a commandto perform a controlled descent to a predetermined depth; based at leastin part on the command, opening a vent valve to release air from abuoyancy compensation bladder; determining that the aquatic structure isdescending based at least in part on the data; closing the vent valve inresponse to determining that the aquatic structure is descending;determining, based at least in part on the data, a difference between adepth level of the aquatic structure and a predetermined depth level;determining that the difference is within a threshold depth level; andactuating, based at least in part on the difference being within thethreshold depth level, an inflation valve to add air to the buoyancycompensation bladder to maintain the aquatic structure within thethreshold depth level.
 22. The aquatic structure of claim 21, whereinthe command is a first command, the operations further comprising:receiving a second command to perform a controlled ascent function;based at least in part on the second command, opening the inflationvalve to add air to the buoyancy compensation bladder; determining,based at least in part on the second command and the data, that theaquatic structure is ascending; and closing the inflation valve.
 23. Theaquatic structure of claim 22, the operations further comprising:maintaining the aquatic structure at the predetermined depth for apredetermined amount of time.
 24. The aquatic structure of claim 23, theoperations further comprising: after an elapse of the predeterminedamount of time, performing the controlled ascent function.
 25. Theaquatic structure of claim 21, wherein the buoyancy compensation bladderis a first buoyancy compensation bladder, wherein the command is a firstcommand, and wherein the vent valve is a first vent valve, theoperations further comprising: receiving a second command to perform aroll function; opening the inflation valve to add air to the firstbuoyancy compensation bladder; opening a second vent valve to remove airfrom a second buoyancy compensation bladder; determining, based at leastin part on the data, that the aquatic structure is rolling; andmaintaining a depth of the aquatic structure at the predetermined depth.26. A method to control an aquatic structure, the method comprising:receiving a command to configure the aquatic structure to maintain adepth underwater within a threshold depth value of a predetermineddepth; receiving sensor data indicating a first current depth levelunderwater at a first time; determining that the first current depthlevel is above the predetermined depth; determining, based at least inpart on the sensor data, that the aquatic structure is associated with aneutral buoyancy; opening a vent valve to release air from a buoyancydevice of the aquatic structure; determining an ascent rate of theaquatic structure is within a predetermined ascent rate; closing thevent valve; determining that a second current depth level at a secondtime after the first time is within a threshold level with respect tothe predetermined depth; and based at least in part on the secondcurrent depth level being within the threshold level, actuating aninflation valve to add air into the buoyancy device.
 27. The method ofclaim 26, further comprising: determining that the second current depthlevel is deeper than the threshold level below the predetermined depth;and actuating the inflation valve to add additional air into thebuoyancy device.
 28. The method of claim 27, further comprising:determining, based at least in part on the sensor data, the aquaticstructure is associated with the neutral buoyancy at the predetermineddepth; determining, at a third time after the second time, that theaquatic structure is drifting downward; and actuating the inflationvalve to add additional air into the buoyancy device.
 29. The method ofclaim 26, further comprising: receiving an indication that an air levelof the aquatic structure is below an air threshold; actuating theinflation valve to add a predetermined amount of air into the buoyancydevice; and transmitting a signal indicating that the air level of theaquatic structure is below the air threshold.